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            <div><h4 class="title">
                <a name="asio.reference.read_until.overload14"></a><a class="link" href="overload14.html"
                                                                      title="read_until (14 of 24 overloads)">read_until
                (14
                of 24 overloads)</a>
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    <p>
        Read data into a streambuf until some part of the data it contains matches
        a regular expression.
    </p>
    <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span>
    <span class="keyword">typename</span> <a class="link" href="../SyncReadStream.html"
                                             title="Buffer-oriented synchronous read stream requirements">SyncReadStream</a><span
                class="special">,</span>
    <span class="keyword">typename</span> <span class="identifier">Allocator</span><span class="special">&gt;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span
                class="identifier">read_until</span><span class="special">(</span>
    <span class="identifier">SyncReadStream</span> <span class="special">&amp;</span> <span
                class="identifier">s</span><span class="special">,</span>
    <span class="identifier">asio</span><span class="special">::</span><span
                class="identifier">basic_streambuf</span><span class="special">&lt;</span> <span class="identifier">Allocator</span> <span
                class="special">&gt;</span> <span class="special">&amp;</span> <span class="identifier">b</span><span
                class="special">,</span>
    <span class="keyword">const</span> <span class="identifier">boost</span><span class="special">::</span><span
                class="identifier">regex</span> <span class="special">&amp;</span> <span
                class="identifier">expr</span><span class="special">,</span>
    <span class="identifier">asio</span><span class="special">::</span><span class="identifier">error_code</span> <span
                class="special">&amp;</span> <span class="identifier">ec</span><span class="special">);</span>
</pre>
    <p>
        This function is used to read data into the specified streambuf until the
        streambuf's get area contains some data that matches a regular expression.
        The call will block until one of the following conditions is true:
    </p>
    <div class="itemizedlist">
        <ul class="itemizedlist" type="disc">
            <li class="listitem">
                A substring of the streambuf's get area matches the regular expression.
            </li>
            <li class="listitem">
                An error occurred.
            </li>
        </ul>
    </div>
    <p>
        This operation is implemented in terms of zero or more calls to the stream's
        read_some function. If the streambuf's get area already contains data that
        matches the regular expression, the function returns immediately.
    </p>
    <h6>
        <a name="asio.reference.read_until.overload14.h0"></a>
        <span><a name="asio.reference.read_until.overload14.parameters"></a></span><a class="link"
                                                                                      href="overload14.html#asio.reference.read_until.overload14.parameters">Parameters</a>
    </h6>
    <div class="variablelist">
        <p class="title"><b></b></p>
        <dl>
            <dt><span class="term">s</span></dt>
            <dd><p>
                The stream from which the data is to be read. The type must support
                the SyncReadStream concept.
            </p></dd>
            <dt><span class="term">b</span></dt>
            <dd><p>
                A streambuf object into which the data will be read.
            </p></dd>
            <dt><span class="term">expr</span></dt>
            <dd><p>
                The regular expression.
            </p></dd>
            <dt><span class="term">ec</span></dt>
            <dd><p>
                Set to indicate what error occurred, if any.
            </p></dd>
        </dl>
    </div>
    <h6>
        <a name="asio.reference.read_until.overload14.h1"></a>
        <span><a name="asio.reference.read_until.overload14.return_value"></a></span><a class="link"
                                                                                        href="overload14.html#asio.reference.read_until.overload14.return_value">Return
        Value</a>
    </h6>
    <p>
        The number of bytes in the streambuf's get area up to and including the
        substring that matches the regular expression. Returns 0 if an error occurred.
    </p>
    <h6>
        <a name="asio.reference.read_until.overload14.h2"></a>
        <span><a name="asio.reference.read_until.overload14.remarks"></a></span><a class="link"
                                                                                   href="overload14.html#asio.reference.read_until.overload14.remarks">Remarks</a>
    </h6>
    <p>
        After a successful read_until operation, the streambuf may contain additional
        data beyond that which matched the regular expression. An application will
        typically leave that data in the streambuf for a subsequent read_until
        operation to examine.
    </p>
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